Air and gas mixing device



Sept, 27, 1932. w. w. KEMP ET AL 1,380,141

AIR AND GAS MIXING DEVICE Filed June 23. 1930 3 Sheets-Sheet l Jwumtow Sept. 27, 1932. w. w. KEMP ET AL AIR AND GAS MIXING DEVICE Filed June 23. 1930 3 Sheets-Sheet 2 Sept. 27, 1932. w w E 1,880,141

AIR AND GAS MIXING DEVICE Filed June 23. 1930 3 Sheets-Sheet 3 gwomtow Patented Sept. 27, 1932 ream VIII-LIAM W'ALLAGE KEMP AND WILLIAM E. VAN HORN, OF BALTIMORE, MARYLAND, ASSIGNORS TO THE C. M. KEMP MAN UFACTURING COMPANY, OF BALTIMORE, MARY- LAND,- A CORPORATION OF. MARYLAND V V I AIR AND GAS MIXING DEVICE Application filed June 23, 1930. Serial No. 463,205.

The present invention relates to improvements in devices for mixing air and gas, particularly adapted for providing a combustible mixture for use in industrial plants or for domestic use.

By the means hereinafter described, it is possible to provide a mixture of illuminating gas and air in which the two constituents are accurately proportioned as desired, and by means of which the mixturewill be supplied to a supply pipe in accordance with the demand. Apparatus embodying the invention insures maintenance of a predetermined quality of mixed air and gas regardless of great variation in the volume delivered. By the improvements also the relative proportions of air and gas supplied at any time may be varied as deemed advisable.

In the drawings:

Figure 1 is an elevation of a mixing device embodying the present improvements.

Figure 2 is a plan, on an enlarged scale, of p the valve mechanism of the mixing device, being substantially on the line 2-'-2 of Figure 1.

Figure 3 is a view partially in vertical sec-- tion and partly in elevation, substantially on the line 3-3 of Figure 2.

Figure 4 is a sectional view substantially on the line 44 of Figure 2.

Figure 5 is a section substantially on the line 55 of Figure 2.

c Figure 6 is a sectional view, on an enlarged scale, of the valve means.

Figure 7 is a plan, substantially on the line 77 of Figure Figure 8 is a view, similar to Figure 6, showing the valve in a different position.

Referring to the drawings, in the several views of which like parts are designated by the same reference characters, the embodiment of the invention illustrated comprises a gas supply main 1, the flow of gas through which is controlled by an automatic regulator within a casing 2, and the outlet 3 of which casing communicates with a gas inlet port 4, provided in the bottom of a mixing chamber that will be hereinafter more particularly described.

Any suitable form of regulating means may be provided in the casing 2, for example, such as is disclosed the copending application of William Hunt, Serial No. 443,813.

The mixing chamber referred to comprises a suitable base 5, and a dome-like cover 6, having at its lower end a flange which is detachably connected, as by bolts or screws 7, to the case 5.

In the base 5 are provided gas and air inlets 4, 8,'the former-being connected with the gas supply pipe 3, and the latter with a short air intake pipe or tube 9. I

On the base 5 of the mixing chamber is mounted a hollow, pedestal-like member 10. having two independent passages 11, 12, which communicate, respectively, with the gas and air inlets. On the upper end of the pedestal-like member 10 is secured a valve seat 13, which is provided with two'series of I ports that communicate, respectively, with '1 the gas and air inlets through the conduits or passages 11, 12.

As shown, the valve seat has three (3) gas ports 14, 15, 16, and a corresponding number of air ports 17, 18 and 19, said ports being arranged in parallel relation, as shown in the drawings, so that a single slide valve is adapted to control passage of gas and air through said ports simultaneously.

7 On the valve seat 13 is supported a recipro cable slide valve 20, which is provided with parallel cross bars 21, 22,'that are adapted to be moved over the air and gas ports of the valve seat to vary the efi'ective open area thereof. Each of the cross bars 21, 22, and the body of the valve 20 controls a pair of air and gas ports, so that as the valve is reciprocated the volume of air and gas admitted to the in terior of the'mixing chamber will be varied.

Preferably, as shown particularly in Figure 6, the members of the valve and valve seat are so related, that when a minimum amount of mixture is being supplied through the valve, as for example, a single burner is in use, there will be a very slight passage connecting the ports 16, 19, in the valveseat with the mixing chamber, such passage being indicated at in Figure 6, and the other ports 14, 17 and 15, 18, will be closed.

If the demand for mixture increases (due to opening additional burners or other cause) under the resulting increase in the suction of the pump, the slide valve will be moved to the left (referring .to Figurev 6), thus suc- & cessively bringing the pairs of ports 15, 18,

and 14, 17, into operative relation.

Comparing Figures 6 and 8, it will be seen that the several ports are of such dimensions and so related that the port 16, for example, Will be first opened slightly and then-the port followed by the port 14. All three of the ports referred to will be partly open before the first one (16) has been fully uncovered (see Figure 8). i

That is the opening of the port 16 may have a width of while the widths of openings of the ports 15 and 14 will be, respectively and 12 The intermediate port of either series will open before the first of the series is fully opened and similarly the third of the series will open before either the first or second is fully open.

Reverse movement of the valve will operate to close the pairs of ports in the valve seat gradually and successively. That is, assuming that the valve has been moved to open the ports to the maximum extent, a reverse movement thereof will act to gradually close the several pairs of ports, and the pair 14, 17, will be completely closed before the other pairs (15, 18 and 16, 19, respectively), are completely shut: off and prior to the valve reaching its completely closed position, there will be a relatively small passage connecting the air and gas inlets with the interior of the mixing chamber as shown in Figure 6.

Figure 8 illustrates the valve ina position intermediate that of Figure 6 and full open position.

In the bottom of the mixing chamber is formed a mixture outlet, which communicates with a conduit 30, formed in a depending boss on the bottom of the base 5, and the lower end of such conduitopens into the casing 31 of a diaphragm chamber. The conduit is connected by a pipe 32 with the inlet of a suitable pump or compressor 35, the outlet 36 of which is adapted to supply combustible mixture to a burner or burners, not shown.

The pump is preferably of the character of that referred to in our prior Patent 1,771,223, although other specifically different forms of pumps, such as are commonly employed with devices of the same general character as the subject matter of the present invention may be employed.

The diaphragm in the casing 31 is shown as; having a weight 40 connected therewith,

and a stem or rod 41 extends upward from such diaphragm through the mixture outlet of the mixing chamber and is connected to means for actuating the slide valve inaccordance with movement of the diaphragm as induced by suctionofthe pump through conduit 32.

As shown, the mixture outlet from the mixing chamber includes a plurality of apertures 29, arranged concentrically about the diaphragm rod 41.

On the upper end of the rod 41 is mounted a yoke 50, the arms of which are connected by a cross rod 51, which extends through a fork at the outer end of an arm 52 on a rock shaft 53, which extends beneath the valve seat and is mounted in suitable bearings rising from the base 5 of the mixing chamber. Arms connected to and rising from the rock shaft 53 engage trunnions at opposite sides of the valve 20, whereby as the shaft 53 is rocked, through the arm 52 and rod 41, by movement of the diaphragm, the valve will be reciprocated over the valve seat to vary the extent of opening of the ports in said seat.

In order to enable the parts to be adjusted so that the proportion of gas. and air supplied at any time may be varied, means are provided for moving the valve on the valve seat in a direction transverse to the reciprocatory path thereof, so that the open portions of the gas and air ports in the valve seat can be made to have different dimensions.

As shown, such means includes a shaft -journalled in suitable bearings in the base 5 of the mixing chamber, and provided at its outer end with a hand wheel 71. On a threaded section of this shaft 79 is fitted an internally threaded sleeve 7 2having an upwardly extending fork, the arms of which are provided at their. free ends withinwardly extending studs that project intoan annular groove onthe shaft 53.

By rotating the shaft 70, the shaft 53 and the valve connectedtherewith willbe bodily adjusted so that the effective area of the gas 1 andairports in the valve seat can be varied as may. be desired, to provide the desired proportion of air and gas.

A manually ad ustable lock or set screw 76 may be provided for retaining the shaft 70 .whenthe valve is in desired adjusted position.

The manner of operation of the improvements may be briefly described as follows:

When the pump 35 is inactive and there is no demand for mixture from the supply pipe 36, thevalve will be completely closed. As soonas a burner, for example, is opened, the suction of the pump will, through its action on the diaphragm in the casing31 andthe connection ofsuch diaphragm with the "alve 20, actto move thev latterto the left into po- 1 sition shown in Figure 6, thus providing a very. slight. opening of ports 16, 19. The mixture from the mixing chamber will pass through the mixture outlets 29 and conduits 30,. 32, to thepump.

Ifthe demand for mixture is increased, as by turning on additional burners, ,forexample, the valve. will be moved furtherto the left gradually and successively opening the several ports until all of the ports in the seat 13 are opened to the maximum extent. If the demand for mixture decreases, the valve will be correspondingly shifted to the right gradually cutting off the supply of air and gas to the mixing chamber.

The pump can be constantly operated, and preferably is of a capacity exceeding that which will be required at any time, and of such character that a small quantity of mixture may be by-passcd therethrough when the valve is completely closed.

It will be noted that the parts are of very simple construction and minimum number. By removing the hood or cover 6, all of the valve mechanism is readily accessible, and the parts thereof can be replaced if necessary. The slide valve is of such form that the suction of the pump does not act to bind it to the seat so that it may be readily moved by slight variations in the position or move ment of the diaphragm in casing 81.

The automatic gas regulator in the casing 2 will control the pressure of flow of gas to the mixing chamber and a suitable valve may be provided in the air supply pipe 9 to close such conduit when the pump is not exerting a predetermined suction force, said valve being of a type to prevent outward flow from the mixing chamber through the pipe 9.

VVcclaim;

1. In an air and gas mixing device, the combination of a mixing chamber comprising a base having independent air and gas inlets and a mixture outlet formed therein, a conduit depending from the base of the mixing chamber and communicating with the mixture outlet, a valve seat supported within the mixing chamber and provided with two series of ports, which series communicate, respectively, with the air and gas inlets, an apertured slide valve cooperating with said seat, a. rock shaft within the mixing chamber having two arms positioned at opposite sides of the valve seat and connected to the valve, a diaphragm chamber communicating with the lower end of said (ZODClUi, a diaphragm in the diaphragm chamber, connections between the diaphragm and said rock shaft, where v the valve will be actuated by movement of the diaphragm to shift the valve and vary the amounts of gas and air admitted to the mixing chamber, and a pump having its inlet connected with said outlet conduit.

2. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a. valve seat provided with two series of ports, those of one series being in communication with the air inlet and those of the other series being in communication with the gas inlet, a slide valve on said seat provided with a plurality of ports each adapted to be positioned over portions of ports in both of the series of ports'in the valve seat, a pump having its inlet connected with the mixture outlet, and means controlled by suction of the pump for moving the valve to shift the ports thereof into and from alignment with the ports in the valve seat, the ports in the valve and seat being so related that the seat ports will be rendered operative successively.

'3. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a valve seat in the mixing chamber provided, with two-series of substantially rectangular ports, the ports in one series being in substantial alignment with those in the other and the ports of the two series being, respectively, in communication with the air and gas inlets, a slide valve on said seat having a plurality of parallel ports each of which is adapted to be positioned over aligned ports of'the two series of ports in the valve seat, the ports in the seat and valve being so related that one of the pairs of ports in the seat is initially placed incommunication with the mixingwchamber and other of said pairs are brought successively into communication with said chamber by movement of the valvein one direction and closed by movement of the valve in the opposite direction, a. pump having its inlet connected with the mixture outlet, and means controlled by suction of the pump for reciprocating the valve on its seat. I

4. In an air andgas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a valve seat within the mixing chamber and elevated from the bottom thereof,

seat, a rock shaft extending beneath the valve seat, arms on said shaft engaging opposite sides of the valve, a diaphragm chamber in communication with the mixture outlet, a diaphragm in said chamber, another arm on the rock shaft, connections between the last said arm and the diaphragm extending through the mixture outlet, and a pump having its inlet in communication with the mixture outlet.

5. In an air and gas mixing device, the combination of a mixing chamber having in.- dependent air and gas inlets and amixture outlet formed in its base, a valve seat elevated from the base of the mixing chamber and provided with ports communicating respectively with theair and gas inlets,'a valve adapted to slide on said seat to control flow of air and gas through the ports of the latter, a rock shaft within the mixing chamber extending transversely of the path of movement of the valve and having arms connected to opposite sides of the valve, a diaphragm chamber communicating with the mixture outlet, a diaphragm in the diaphragm chamber, a rod connected to the diaphragm and extending through the. mixture outlet, into the mixing chamber, an arm on the rock shaft engaged with the end of the rod in the mixing chain ber, and a pump having its inlet in communication with the mixture outlet.

6. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a valve seat in said chamber having two series of ports respectively communicating with the air and gas inlets, a valve adapted to reciprocate on said seat to con trol flow of gas and air through said ports, a rock shaft within the mixing chamber extending transversely of the path of movement of the valve and provided with arms that engage the valve at opposite sides thereof, a fork-like member having its arms engaged with said shaft and having an internally threaded body, a shaft operable from outside the mixing chamber and having a threaded section engaged with said thread in the body of the fork-like member, a pump having its inlet connected with the mixture outlet, and means controlled by suction of the pump for rocking the valve actuating rock shaft.

7. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a valve seat in said chamber having two series of ports respectively communicating with the air and gas inlets, a valve adapted to reciprocate on said seat to control flow of gas and air through said ports, a rock shaft journaled in bearings within the mixing chamber and extending transversely of the path of movement of the valve, arms carried by said shaft and engaging the valve at opposite sides thereof, a shaft ournaled in bearings in the base of the mixing chamber and extending across a cavity in the bottom of said chamber, a fork-like member having an internally threaded body engaging a threaded section of said shaft and a pair of arms engaging the rock shaft without interfering with oscillation thereof, a pump having its inlet connected with the mixture outlet, and means controlled by suction of the pump for rocking the valve actuating rock shaft.

8. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a pump having its inlet connected with the mixture outlet, and means controlled by suction of the pump for regulating flow through the air and gas inlets comprising a plurality of ports and a valve movable across said ports, the ports and valve being so related that the ports will be successively opened as the'suction of the pump increases and that all of them will be open to some extent prior to the first in the series being opened to the maximum.

9. In an air and gas mixing device, the combination of a mixing chamber! having independent air and gas inlets and a mixture outlet, a valve seat provided'with two series ofports, those of one series being in communication with the air inlet and those of the other series being in communication with the gas inlet, a pump having its inlet connected with said mixture outlet, and'a valve controlled'by suction of the pump and movable over all of said ports, the ports and valve being so related that the latter will, under a predetermined degree of suction by the pump, initially open one of the pairs of air and gas ports to a slight extent and under the effect of increased suction will increase the opening of said ports and simultaneouslyopen another pair of said ports.

10. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a valve seat provided with two series of ports, those of one series being in communication with the air inlet and those of the other series being in communication with the gas inlet, and the ports in one series being arranged in substantial parallel relation to those in the other series, a pump having its inlet connected with the mixture outlet, a valve controlled by suction of the pump for opening and closing all of said ports, said valve acting to open the pairs of air and gas ports successively and in such manner that all of them may be partly opened before any pair is opened to the maximum extent.

11. In an air and gas mixing device, the combination of a mixing chamber having independent air and gas inlets and a mixture outlet, a substantially horizontal valve seat within the mixingchamber provided with two series of ports, those of one series communicating with the gas inlet and those of the other series being in communication with the air inlet, pump having its inlet connected with the mixture outlet, and a slide valve movable on the valve seat by means controlled by variations in the suction of the pump, movement of the valve under a predetermined amount of suction acting to partly open only one pair of air and gas ports and further movement of the valve, under increase of suction by the pump opening other pairs of said ports successively prior to the firstsaid pair being opened to their maximum extent.

In testimony whereof we have hereunto set our hands.

WILLIAM WVALLAOE KEMP. WVILLIAM H. VAN HORN. 

